From here, I plugged in the English name of the place and copied the Chinese address after clicking on the map. The address is:

北京市西城区前门西大街甲10号（全聚德烤鸭店（和平门店）的东侧）

The bit after the 10号 is an explanatory note for the driver, giving the name of a building nearby.

The photo of the hotel front on this site shows the phone number as 63026066. Presumably, that's a Beijing number and if you're calling from a cell phone or from outside of Beijing, you'll have to first dial the city code 010. Drop the first 0 if calling from overseas.

A number of reviews indicated the hotel smelled of tobacco. Apparently, they don't distinguish between smoking and non-smoking rooms. If you're a non-smoker, this might be of interest to you.